Numerous depth gauge means are known. For example, U.S. Pat. No. 4,986,200 in the name of Johnston entitled Depth Gauge Wheel is directed to a wheel removably securable to a coulter disc to control the cutting depth of the disc, wherein the wheel is formed of a high density plastic to which soil and debris are said not to adhere. Another U.S. Pat. No. 4,423,788 in the name of Robinson et al. discloses an agricultural furrow forming apparatus depth control.
A more recently issued U.S. Pat. No. 5,452,768 in the name of Korberlein, assigned to Worksaver, Inc. of Litchfield Ill. discloses a tillage implement to be pulled behind a tractor having a conventional frame with one or more furrowing elements depending from the frame or plough share. Each furrowing element has a disc-like coulter, a shank, and a replaceable plough share mounted on the soil engaging end of the shank. One or more gauge wheels can be adjusted to vary the height of the implement from the soil so as to adjust the depth of the tillage extending down from the frame.
U.S. Pat. No. 5,609,114 to Barton describes an apparatus for agricultural seeding, the apparatus having a rotating coulter disk that is inclined both with respect to the vertical and the horizontal, and a furrow-closing packer wheel that is also inclined with respect to the vertical and the horizontal, the vertical inclination angle being in the opposite direction than the respective angle of the coulter disk.
Although many of these devices appear to perform their intended function, there is a need for an easy-to-adjust depth adjustment mechanism that will enable the positioning of the coulter blade, or another ground-opening, furrow forming element relative to the closing element or another associated ground engaging element.
It is therefore an object of the invention to provide an improved depth adjustment mechanism for an agricultural implement including an opener element (hereinafter termed simply "opener" for brevity) coupled with a ground surface engaging element, e.g. a closing element, the depth adjustment mechanism linked to the opener and to the ground surface engaging element (hereinafter abbreviated as GSE element), wherein the height of the GSE element can be adjusted relative to the opener to control the relative height, typically also the cutting depth, of the opener while maintaining a predetermined angle between the coulter element and the GSE element, the height adjustment being accomplished with a substantially linear motion.
Preferably, for reasons explained hereinbelow, the GSE element is a ground closing element, but it can also be another element.
In accordance with the invention, there is provided, generally, a seeding or fertilizing implement intended to be moved in a line of travel, comprising:
a frame,
an opener extending from the frame, said opener defining a verticalmost axis,
a seed or fertilizer delivery mechanism disposed substantially behind the opener in the line of travel,
a GSE element disposed substantially in the line of travel behind the delivery mechanism, and
a tool adjustment mechanism linked to the opener and to the GSE element for adjusting the relative height between the opener and the GSE element.
The tool adjustment mechanism comprises
a first arm linked with the opener,
a second arm linked with the GSE element,
the first arm and the second arm having each an engaging surface matching each other, and
a releasable locking means for biasing the engaging surfaces together such as to immobilize, or lock the surfaces during operation.
The engaging surfaces when not biased to each other, are substantially linearly movable relative to each other in a plane substantially parallel to the verticalmost axis of the opener, whereby the opener and the GSE element remain at a substantially constant angle throughout depth adjustments of the mechanism.
Advantageously, the implement in accordance with the invention provides a closing element, e.g. a closing wheel, that is adjustable in height relative to the opener, e.g. a coulter wheel, in a plurality of positions, without the use of tools, while substantially maintaining a predetermined angle between the coulter wheel and the closing wheel. Furthermore, at any height adjustment, the coulter wheel and closing wheel are maintained in relative position such that the closing wheel (or closing element) substantially follows the line of travel of the coulter wheel.
In an embodiment of the invention, there is provided an agricultural implement having a support frame, a rotatable coulter blade or wheel and a rotatable closing wheel depending from the support frame and forming a predetermined angle between the blade and the wheel, the predetermined angle being substantially constant as the closing wheel and coulter blade or wheel are relatively height-adjusted; the closing wheel being rotatable on an axle depending from a member having a lower arm and an upper arm, the lower arm depending from the upper arm at an elbow, the upper arm having means for engaging with complementary engaging means on or attached to the support frame, and means for bringing together said engaging and complementary means into a releasable locking engagement.
In accordance with the invention, there is further provided, a system for opening and closing ground comprising an opener, e.g. a coulter wheel, for cutting and opening the ground at a first predetermined angle, and a GSE element ,for example a closing element for following the coulter wheel for closing the ground, the GSE element engaging the ground at a second predetermined angle, the GSE element being adjustable in height relative to the coulter wheel, with the GSE element being adjusted at a plurality of adjustable heights, while in use, substantially maintaining the angles and maintaining the coulter wheel and GSE element in a relative position such that the portions of the wheels engaging the ground traverse a substantially same location, or in other words, the closing wheel engages the ground substantially in the line of travel of the coulter wheel such that the GSE element engages the ground substantially where the coulter wheel has cut the ground.
In yet another aspect of the invention, the implement may comprise two openers and a tool adjustment mechanism as defined above, the mechanism linked to both the openers for setting a relative height, or vertical position, between the openers. In such a case, the geometric relationship as described herein would apply correspondingly to said openers, i.e. the tool adjustment mechanism is provided to allow one of the openers to move parallel to the verticalmost axis of the other opener.
In one embodiment, the invention provides a depth adjustment mechanism having a first arm linked with the opener, a second arm linked with the GSE element, said first arm and said second arm having each an engaging surface matching each other, and a releasable locking means for biasing said engaging surfaces together such as to immobilize them during operation. The height of the GSE element relative to the opener may be adjusted by positioning a lever such that the wheel is movable into a plurality of positions for controlling the depth of the opener coupled therewith. When the GSE element is moved, the relative angle between the opener and GSE element is maintained and more importantly the closing wheel traverses the same location at a predetermined complementary angle that allows the open soil to be closed by the GSE element.